In the manufacture of photographic film and paper, the film and paper are exposed to many different environments as they move through the base manufacturing, sensitizing, and finishing process areas. Occasionally, photographic products can become contaminated with iron particles. Iron being a photographically active material, is a more undesirable contaminant than other nonphotographically active particulate matter. Since iron is used in many machine parts it is inevitable that through normal wear and general part failure iron contamination is going to occur. Iron is also present in indoor and outdoor environmental air, and comes from many sources. Iron can also be brought into buildings on people's feet, product boxes and wheels, product handling trucks and dollies. The much larger (greater than 10 microns) particles of iron do not remain airborne for long once generated. However, it has long been known that much smaller iron particles including submicron sized particles are often generated and made airborne prior to the generation of larger iron particles. These particles can remain airborne for significant periods of time based on their physical size and environmental conditions. Larger particle generation is associated with catastrophic component failure. When this happens there usually will be some level of product waste associated with these contamination events.
There is a need for a way to detect airborne iron particulate matter. The present invention satisfies this need with an apparatus which detects the early warning signs of iron component failure and the presence of high iron contamination in the ambient air.